Name: _____________________________SID:_____________________________Bis098-400 (Bis2A Pilot) First Midterm ExamJanuary 31, 2007Put answers and name on Scantron Sheet 1.Biology is an experimental science in which conclusions must be based on evidence. Yet some people say that science cannot prove that anything is true, but can only prove that an alternative idea is wrong. Which statements below agree with this philosophy?a)There may always be some alternative (yet unknown) idea that fits the your data just as well as the idea you’d like “prove”. b)Sometimes the rules governing nature change after you do an experiment.c)Eliminating an incorrect possibility brings you marginally closer to understanding how something works.d)All of the above.e)Both the first and last choice (a and c).2.The reaction A + B <-> C + D comes to a steady state at a point that favors products, C and D. That is, [C]x[D] > [A]x[B]. Which of the following statements is correct?a)The Keq is > 1.b)The free energy change for the reaction as written (∆Go) is positive.c)The activation energy is greater for the forward than for the reverse reaction.d)The forward reaction rate will increase if you increase the concentrations of C and D.e)Both answers a and d are correct (above).In the figure below, which lettered value best fits each of the descriptions that come after the figure (Questions 3-7). Any letter can be used more than once and some letters may not be needed.1Progress of a reactionEnergyof inputcompounds(A and B)(b)(a)(c)(d)(e)

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Name: _____________________________3.This value in the figure above dictates the concentrations of reactants at steady state and is not changed by either heat or the presence of a catalyst. ___________ (insert some letter, a-e)4.This value in the figure above dictates the forward reaction rate constant, at any temperature, with or without a catalyst. ___________ (insert some letter, a-e)5.This value in the figure above is affected by heat but not by the presence of a catalyst ________ (insert some letter, a-e)6.This value in the figure above is affected by the presence of a catalyst but not by heat. ________ (insert some letter, a-e)7.This value in the figure above dictates the forward rate constant and is decreased by both heat and a catalyst. -________ (insert some letter, a-e)8Which of the possibilities best explains why life uses protein catalysts rather than heat to increase the rate of reactions?a)heat is expensive to generateb)protein catalysts can be extremely specific for one reactionc)enzymes are unstable and denature at high temperatured)a protein catalyst (but not heat) can decrease the activation energy foronly the forward reaction.e)none of the above 9.Based on your understanding of protein structure, do you expect that there might be multiple sequences of 300 amino acids that are different from each other at every position and still successfully fold and catalyze a particular reaction equally well?

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